首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   15597篇
  免费   265篇
各国政治   479篇
工人农民   1276篇
世界政治   678篇
外交国际关系   535篇
法律   9633篇
中国政治   50篇
政治理论   3169篇
综合类   42篇
  2020年   105篇
  2019年   131篇
  2018年   1396篇
  2017年   1346篇
  2016年   1173篇
  2015年   193篇
  2014年   188篇
  2013年   750篇
  2012年   365篇
  2011年   1091篇
  2010年   1154篇
  2009年   728篇
  2008年   925篇
  2007年   895篇
  2006年   241篇
  2005年   243篇
  2004年   370篇
  2003年   345篇
  2002年   198篇
  2001年   322篇
  2000年   305篇
  1999年   225篇
  1998年   103篇
  1997年   87篇
  1996年   103篇
  1995年   99篇
  1994年   99篇
  1993年   65篇
  1992年   145篇
  1991年   160篇
  1990年   141篇
  1989年   158篇
  1988年   136篇
  1987年   152篇
  1986年   136篇
  1985年   155篇
  1984年   130篇
  1983年   146篇
  1982年   97篇
  1981年   96篇
  1980年   71篇
  1979年   105篇
  1978年   84篇
  1977年   78篇
  1976年   57篇
  1975年   47篇
  1974年   58篇
  1973年   60篇
  1971年   51篇
  1970年   47篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
961.
Puberty has been related to the onset of a variety of weight concerns and eating problems among middle school girls, including body dissatisfaction, dieting, and eating disorders. At least two models can be used to explain these relationships. The first emphasizes the timing of puberty, arguing that girls who face early puberty are particularly stressed because of the off-time nature of the event. The second focuses on synchronous events. For girls more than boys, puberty is likely to coincide with the change from elementary to middle school and/or beginning to date. Such synchronous events may create greater stress for girls. Seventy-nine girls were tested during the spring of their sixth- and eighth-grade years. Pubertal and dating status, body dissatisfaction, weight management, and eating disordered attitudes (using the Children's EAT:ChEAT) were assessed. The simple timing model (early vs. on time vs. late) was not supported. The simple synchronous model received some support in that girls with synchronous onset of menstruation and dating had higher ChEAT scores as well as greater body dissatisfaction. However, the data indicated that girls for whom puberty was early and coincidental with dating might be at unusual risk. These girls showed the highest levels of body dissatisfaction and the highest ChEAT scores.Ph.D. from Temple University. Research interest is in developmental psychology.Ph.D. from the University of California at Santa BarbaraThese authors have a joint research program in the developmental psychopathology of eating problems.The first wave of data for this report was collected as part of her undergraduate honors thesis.Earlier versions of these data were presented at the 1991 meeting of the Society for Research in Child Development, Seattle, Washington and the 1992 Conference on Human Development, Atlanta, Georgia.  相似文献   
962.
The progressivity and equity of both state and federal individual income taxes, as well as the combined system of both taxes, are examined before and after the federal Tax Reform Act of 1986 using a variety of measures applied to federal Statistics of Income individual income tax data; state taxes are calculated using TAXSIM. Our findings are as follows: First, in both 1985 and 1987, state personal income taxes were generally less progressive and more horizontally equitable than the federal system. Second, in moving from 1985 to 1987, state personal income tax systems generally displayed decreased progressivity and horizontal inequity. The combination of the two systems displayed generally lower progressivity and horizontal equity scores when we compare 1987 to 1985. Last, the after-tax income distribution became more unequal when we compared 1987 to 1985.  相似文献   
963.
The U.S. federalist public economy is an ever-evolving system of financing and expenditure responsibilities between local, state, and federal governments. The past decades have seen a significant centralization of responsibility for the financing of state and local public services through grants-in-aid and federal tax subsidies. This article advances a model of local constituent influence in central government fiscal policies which seeks to explain this trend, and then examines how strong executive branch and congressional leadership might begin to control the local pressures for central government financing. TRA86 is offered as one example in which this leaedership proved effective. The general lesson is that good fiscal policy in federalist public economies requires not only capable local governments, but central government political institutions with the strength to meet national needs as well.  相似文献   
964.
A 6-year longitudinal panel study investigated the absolute and relative stability in depressed mood throughout adolescence by reporting data from a sample of 538 adolescents between 13 and 19 years of age. Results revealed the following. (1) Girls had on average higher depressed mood scores than boys at all ages. (2) Among boys there were no substantial changes in depressed mood mean scores, while among girls there was a slight tendency of a curvilinear trend, with a peak level reached in midadolescence. (3) There was a tendency for adolescents to retain their relative level in depressed mood, most pronounced for a period of 4 years, from age 15 to age 19 years. (4) Depressed mood was most stable in a subgroup of adolescents who had high initial depressed mood scores. (5) By applying structural equation modeling, it was shown that the stable (trait) component of depressed mood increased in importance with increasing age, while the temporal (state) component decreased with increased age.  相似文献   
965.
Journal of Youth and Adolescence - Do mothers' and fathers' attitudes towards their children's academic performance influence children's perceptions of their academic competence?...  相似文献   
966.
967.
968.
An intoxication following administration of morphine, tramadol and atracurium in a suicide case is reported. The route of administration and the amount of the particular drug were known from the investigation of the death scene and the findings of the postmortem examination. Tramadol was present in the gastric contents as well as in blood, liver, kidney and brain samples, whereas the drug could not be detected in muscle. All body fluids and tissues investigated contained morphine as well as its 3- and 6-glucuronides with the exception of muscle tissue. The concentrations of morphine and its glucuronide metabolites were determined by LC/MS following solid phase extraction. Interestingly, the concentration of M6G in brain, liver and kidney were close to the concentration of M3G in the particular tissue. This phenomenon might be explained by a preferential hydrolysis of M3G or by a preferential formation of M6G postmortem. Measurement of morphine and M6G in femoral blood and cerebrospinal fluid may be a useful indicator in rapid deaths.  相似文献   
969.
After surgical treatment of an inguinal hernia, a 26-year-old male was discharged from hospital with a well healing surgical wound. Four weeks later he was admitted again with a major localized painful swelling of the soft tissues, whereas the clinical examination revealed no further local or systemic signs of inflammation. The immediate operation disclosed no abscess formation, but a large colliquation necrosis of the subcutaneous tissue with an outstanding petroleum-like odour. On toxicological examination of the necrotic tissue, a respective petroleum distillate was found. The patient was confronted with the suspicion of having injected the petroleum preparation himself to prolong the wound healing and finally admitted the self-mutilating behaviour. The pathophysiology, clinical history and morphological findings are discussed in comparison with case reports of chemically induced self-mutilation.  相似文献   
970.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号